> The parent seems to be suggesting that a vegan diet didn't work for them for health reasons. But countered objections to this by saying that it's difficult. (Which it is. Stupidly difficult to eat meat, gluten and soy free in my experience) But convenience is a different argument from health. Which is it? If the issue is convenience, I concede. If it's health there may be room to explore other options.

Why can't it be both? A diet can be both medically necessary and inconveniencing. See my own example or a diabetic diet.